\begin{table}
  \begin{center}
  \caption{Physical constants in \ccl. \label{tab:constants_comparison}}
  \begin{tabular}{lccccccccc}
\hline\hline
 & $G_{Newt}$ & $k_b$ & $\sigma_{SB}$ & $h$ & $c$ & eV  & $M_\odot$ & pc \\ 
\hline
NIST & -3.0e-05 & -1.4e-06 & -5.9e-06 & 1.6e-07 & 0.0e+00 & 8.4e-08 & \--- & \--- \\[3pt]
 PDG 2013 & -6.0e-05 & -1.1e-06 & -4.8e-06 & 9.2e-08 & 0.0e+00 & 4.9e-08 & -2.0e-04 & 1.1e-09 \\[3pt] 
GSL & -1.9e-04 & 0.0e+00 & 0.0e+00 & 0.0e+00 & 0.0e+00 & 0.0e+00 & 0.0e+00 & -4.5e-11 \\ [3pt]
CLASS & 0.0e+00 & 0.0e+00 & \--- & 0.0e+00 & 0.0e+00 & 0.0e+00 & \--- & -6.7e-11 
\\\hline\hline
\end{tabular}
\end{center}
\end{table}

